Gyro caging mechanism



0, 1955 P. E. SEIFRIED 2,716,344

GYRO CAGING MECHANISM Filed Feb 15, 1954 INVENTOR. PAUL E. SE/FR/ED 19770RNEV United States Patent GYRO CAGING MECHANISM Paul Seifried, New City, N. Y., assignor to Bendix Aviation Corporation, Teterboro, N. J., a corporation of Delaware Application February 15, 1954, Serial No. 410,115

12 Claims. (Cl. 74-5.1)

This invention relates to gyros, and particularly to gyro erecting or caging mechanisms. Apparatus of this type is used to bring the spin axis of a gyro into proper orien tation relative to the casing or frame, either to restore such orientation while the gyro is in operation, or to hold or place the gyro in proper position when it is not functioning. The invention is especially applicable to gyros mounted on gimbals, where the gyro must be oriented about two axes at right angles to each other.

A gyro of this type may be caged by applying pressure to two cams, one for each axis. This may be done by manually operated devices; but ordinarily considerable compactness, it permits the application of excessive force to the cams and associated mechanisms, if the operator is injudicious, which may derange the extremely precise and relatively delicate parts of gyro-operated instruments.

An object of the invention is to provide a gyro caging mechanism of the direct operation type which includes means for preventing the application of excessive force to the caging cams. Another object is to provide caging mechanisms in which excessive manually exerted force will be applied to frame members and not to the gyro structure.

The invention has been found to be especially advantageous in caging mechanisms of the type in which a caging element slidably mounted at one side of a gyrooperated instrument casing carries a cam-engaging caging member and is manually operated by a knob at one end mounted on the face plate of the instrument. An example of this arrangement is given in the application of Konet et 211., Serial No. 134,038, filed December 20, 1945, assigned to the same assignee, and is indicated generally in my Patent No. 2,655,046, issued October 13, 1953. An object of the invention is to improve arrangements of this type by providing a yieldable connection between the pull rod and the caging member, arranged to apply the requisite caging pressure but to prevent excessive stress on the mechanism, while retaining the simple and compact arrangement and construction of such mechanisms. A further object is to provide an arrangement of the indicated type that will apply the requisite caging pressure to two caging cams or the like in succession, while limiting the maximum pressure to a safe value. Another object is to provide caging means of. the indicated type provided with means for adjusting the caging pressure.

These and other objects and advantages of the invention will appear more fully from consideration of the detailed description which follows, in conjunction with the accompanying drawing, wherein one embodiment of the invention is illustrated. It is to be expressly understood, however, that the drawing is for the purposes of illustration and description and is not to be construed as defining the limits of the invention.

The drawing is a perspective view, partly diagrammatic, of an indicating instrument unit operated by a gimbal-mounted gyro, with the casing removed and parts broken away, the general construction corresponding to that disclosed in the above-mentioned application and patent.

The instrument unit comprises a rigid metal main frame 10, including an integral rear end 11 and a front end 12 carrying front frame 13. The gyro, not shown, rotates in a diagrammatically indicated casing 14 about a normally vertical spin axis, the casing being mounted through trunnions 15 in gimbal yoke 16 carrying a pivot shaft 17 rotatable in bearing 18 on rear frame end 11. This arrangement is well known, and the gyro operating and controlling devices, as well as the indicating mechanism actuated by the gyro, are omitted.

The gyro is erected about the longitudinal gimbal axis by means of a cylindrical cam 19 fixed to shaft 17 and having a cam face 20 sloping axially toward a recess 21. A caging roller 22 aligned with cam face 20 is carried by an arm 23 on caging block 24.v Block 24 likewise carries a second caging roller 25 aligned with a cardioid cam 26 mounted on the adjacent trunnion 15 externally of gimbal yoke 16.

Caging block 24 is freely slidable on a suitable longitudinal guide structure, which in the illustrated embodiment includes a guide rod 27 fixed at its ends to the front end 13 of main frame 10, and to supporting plate 28 mounted on and spaced from the rear end 11 of the main framev 10, rod 27 passing slidably through a suitable guide bore in block 24.

The block 24 is also guided by caging rod 29, slidably mounted in plate 28, frame end 12 and front frame 13, the forward end of rod 29 carrying a pull knob 30 normally bearing against the front face of frame 13. A spiral return spring 31 on rod 29 bears at one end against the from main frame end 12 and at the other end against an abutment on caging rod 29, formed in the illustrated embodiment by collar 32 fixed to the latter rod.

Spiral caging spring 33 on rod 29 bears at one end against block 24,v which in the illustrated form is cut away to clear the spring and provide a flange 34 in which rod 29. is, slidably mounted and which abuts the end of spring 33 at one side and collar 32 at the other side; The other end of spring 33 engages a longitudinally adjustable abutment on rod 29, which in the illustrated embodiment is a nut 35 held in place by lock nut 36,

this portion of rod 29 being suitably threaded. Beyond supporting plate 28, in which the rod 29 is slidably mounted, said rod may be provided with a stop abutment, which in the illustrated form consists of a stop nut 37 held in adjusted position by lock nut 38.

In operation, return spring 31 will hold caging rod 29 in retracted position with knob 30 against front frame 13', and with cam rollers 22 and 25 spaced from. caging cams 19 and 26, so that the gyro 14 is free to move in its gimbal support without interference. Return spring 31 must be sufliciently strong to compress caging spring 33 far enough to hold block 24 in correct retracted position.

When it is desired to cage the gyro, knob 30 is manually pulled, compressing spring 31 and shifting col.- lar 32 away from flange 34, allowing block 24 to move forward under the pressure of caging spring 33, which is simultaneously compressed by nut 35, moving block 24 forward until caging roller 22 engages cam face 20 and exerts rotary stress on pivot shaft 17, bringing the trunnion yoke 16 into transversely aligned position. Caging roller 25 engages trunnion cam 26 and rotates trunnion 15 to bring gyro 14 into longitudinally aligned position.

The pressure on caging rollers 22 and 25 is exerted by spring 33, and not directly by the manual pull on knob 30, as in previous arrangements. This pull may be limited by the compression of return spring 31;to solid position, and any further stress will be applied directly to the frame end 12 and not to the gyro mechanism. If a stop abutment on rod 29 such as nut 37 is employed, this will serve to limit the manual pull; and further manual stress will then be exerted against plate 28 and the rear end frame 11.

It will be evident that the throw of rod 29, and the position in which said rod is stopped during caging movement, can be adjusted by changing the position of stop nut 37. Likewise, the caging pressure exerted on block 24 and caging rollers 22, 25 by spring 33 can be adjusted by changing the position of nut 35. When the gyro 14 is caged, spring 33 should still exert enough pressure to hold the gyro in place. The release of knob 30 will permit the return spring 31 to shift caging rod 29, block 24 and associated parts into their original position, in which gyro 14 is free for movement in any direction in its trunnion support.

While the operation of the invention has been described as caging in the interests of simplicity, it will be understood that the same operation may be carried out for the purpose of positively positioning the gyro with its spin axis in predetermined orientation, an operation sometimes referred to as erecting; and all such operations are referred to herein as caging.

Although but one embodiment of the invention has been illustrated and described in detail, it is to be expressly understood that the invention is not limited thereto. Various changes can be made in the design and arrangement of the parts without departing from the spirit and scope of the invention, as it will now be understood by those skilled in the art. In particular. while the invention has been illustrated in connection with a gyro vertical, it can be employed in apparatus for caging gyros having other orientations. Moreover, while it is especially advantageous as an improvement on the earlier caging arrangement referred to above, it includes features that can be applied to other types of caging devices of the slide type.

I claim:

1. Gyro caging mechanism, comprising a caging element, and means for actuating said element to cage and uncage the gyro, including caging spring means bear ng against the caging element, return spring means bearing against the caging element in uncaged position, and actuating means for retracting the return spring means during caging and releasing the return spring means during uncaging.

2. Gyro caging mechanism, comprising a movable caging element, and means for actuating said element to cage and uncage the gyro, including caging spr ng means bearing against the caging element, return spring means bearing against the caging element in uncaged position, and actuating means for shifting the return spring means out of bearing relation to the caging element to allow the caging spring means to actuate said element during caging, and releasing the return spring means for engagement with said element during uncaging.

3. Gyro caging mechanism, comprising a frame, a caging element, and means for actuating said element to cage and uncage the gyro, comprising caging spring means bearing against the caging element, return spring means bearing against the frame and against the caging element in uncaged position, and manually operated actuating means for stressing the return spring means against the frame and away from the caging element during caging and releasing the return spring means during uncaging.

4. Gyro casing mechanism, comprising a caging element, and means for actuating said element to cage and uncage the gyro, including a manually operated actuating member, spring means engaged and actuated by said member for moving the caging element into caging position, stop means for limiting the movement of said member, and spring means for moving the caging element out of caging position when the operating member is released.

5. Gyro caging mechanism, comprising a frame, a caging element, a caging rod slidably mounted on the frame, a caging spring bearing against the caging element, a return spring bearing against the frame and the caging element, arranged to hold the caging element normally in uncaged position, and an abutment on the rod engaging the return spring, arranged to stress the return spring to relieve its stress on the caging element during caging movement and to release the return spring to restore said stress and return the element to uncaged position during uncaging movement.

6. Gyro caging mechanism, comprising a caging element, and means for actuating said element to cage and uncage the gyro, including caging spring means bearing against the caging element, return spring means bearing against said element, and actuating means for applying caging stress to said caging spring means while rendering the return spring means ineffective during caging actuation, and for rendering the return spring means operative and releasing stress on the caging spring means during uncaging actuation.

7. Gyro caging mechanism, comprising a caging element, and means for actuating said element to cage and uncage the gyro, including caging spring means bearing against the caging element, return spring means bearing against said element, and manually operated actuating means for applying caging stress to said caging spring means while rendering the return spring means inactive during manually operated caging actuation, and for rendering the return spring means operative and releasing stress on the caging spring means upon manual release for uncaging actuation.

8. Gyro caging mechanism, comprising a caging element, a frame, a caging rod slidably mounted on the frame, a caging spring bearing against the caging element and the rod, a return spring bearing against the frame and the caging element, arranged to hold the element in uncaged position, and an abutment on the rod engaging the return spring, arranged to stress the return spring to relieve the stress on the caging element while the caging spring stress is increasing during caging movement, and to release the return spring to restore the stress and return the element to uncaged position while reducing the caging spring stress during uncaging movement.

9. Gyro caging mechanism, comprising a caging element, a frame, a caging rod slidably mounted on the frame, a coil caging spring on the rod engaging the caging element, an abutment on the rod engaging the caging element, and a coil return spring on the rod bearing against the frame and the abutment, arranged to hold said abutment against the caging element and retain said element normally in uncaged position, said rod being longitudinally slidable to compress the spring against the frame and shift said abutment away from the caging element during uncaging movement of the rod, the abutment being returned to bearing position for return of the caging element to uncaged position during uncaging movement of the rod.

10. Gyro caging mechanism comprising a caging element, a frame, a caging rod slidably mounted on the frame, a coil caging spring on the rod engaging the caging element, an abutment on the rod normally engaging the caging element, a coil return spring on the rod hearing against the frame and the abutment, arranged to hold said abutment against the caging element and retain said element normally in uncaged position, said rod being longitudinally slidable to compress the spring against the frame and shift said abutment away from the caging element during uncaging movement of the rod, the abutment being returned to bearing position for return of the caging element to uncaged position during uncaging movement of the rod, and a stop on the rod, arranged to engage the frame and limit the caging movement of the rod.

11. Gyro caging mechanism, comprising a caging element, a frame, a caging rod slidably mounted on the frame, an abutment on the rod, a coil caging spring on the rod bearing against the abutment and the caging element, a second abutment on the rod normally engaging the caging element, a coil return spring on the rod hearing against the second abutment and the frame, arranged to hold said element normally in uncaged position, the return spring being compressed against the frame and the caging spring compressed against the caging element by the said abutment during caging movement of the rod.

12. Gyro caging mechanism, comprising a frame, a

guide member carried by the frame, a caging element 1 slidably mounted on the guide member, and means for actuating said element to cage and uncage the gyro, including a caging rod slidably mounted on the frame and caging element, an abutment on the rod normally engaging the caging element, a coil caging spring on the rod bearing against the abutment and the caging element, a second abutment on the rod, a coil return spring on the rod bearing against the abutment and the frame, a pull knob on the end of the rod, said return spring normally holding said abutment against the caging element and said knob against the frame in uncaged position, arranged to compress the return spring against the frame and shift the second abutment away from the caging element while compressing the caging spring against the caging element during manual operation of said knob for caging movement of the rod, and releasing said return spring and simultaneously releasing stress on the caging spring for return of the caging element to uncaged position upon manual release of the knob.

References Cited in the file of this patent UNITED STATES PATENTS 1,955,746 Inglis Apr. 24, 1934 2,459,496 Cahill et a1 Jan. 18, 1949 2,468,016 Konet Apr. 19, 1949 2,641,133 Barkalow et al June 9, 1953 

